is this an algebra class? if so it just
11.50x + 16y = 20.25
Answer:
1 seconds after being thrown, the stone reaches its max height
Step-by-step explanation:
The parabolic (quadratic) equation is:

Lets expand this in the form
, so we have:

We can say the values of a,b, and c, now to be:
a = -5
b = 10
c = 40
The number of seconds at which the max would occur is given by the point, x, at:

We know a and b, let's find the seconds, x,

Hence,
1 seconds after being thrown, the stone reach its max height
( x + 4), (x - 9) = 4x
Hope this helps!
I think this a linear function. The graph has a constant flow of going up. In other words, it is linear.